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Groups > linux.kernel > #1440907
| From | Andy Lutomirski <luto@kernel.org> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH v5 11/32] x86/dumpstack: Try harder to get a call trace on stack overflow |
| Date | 2016-07-11 23:10 +0200 |
| Message-ID | <rTQCK-3Y9-31@gated-at.bofh.it> (permalink) |
| References | <rTQt3-3Fx-3@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
If we overflow the stack, print_context_stack will abort. Detect
this case and rewind back into the valid part of the stack so that
we can trace it.
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
---
arch/x86/kernel/dumpstack.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
index 4eefee06f6fd..de8242d8bb61 100644
--- a/arch/x86/kernel/dumpstack.c
+++ b/arch/x86/kernel/dumpstack.c
@@ -87,7 +87,7 @@ static inline int valid_stack_ptr(struct task_struct *task,
else
return 0;
}
- return p > t && p < t + THREAD_SIZE - size;
+ return p >= t && p < t + THREAD_SIZE - size;
}
unsigned long
@@ -98,6 +98,14 @@ print_context_stack(struct task_struct *task,
{
struct stack_frame *frame = (struct stack_frame *)bp;
+ /*
+ * If we overflowed the stack into a guard page, jump back to the
+ * bottom of the usable stack.
+ */
+ if ((unsigned long)task_stack_page(task) - (unsigned long)stack <
+ PAGE_SIZE)
+ stack = (unsigned long *)task_stack_page(task);
+
while (valid_stack_ptr(task, stack, sizeof(*stack), end)) {
unsigned long addr;
--
2.7.4
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[PATCH v5 00/32] virtually mapped stacks and thread_info cleanup Andy Lutomirski <luto@kernel.org> - 2016-07-11 23:00 +0200
[PATCH v5 18/32] signal: Consolidate {TS,TLF}_RESTORE_SIGMASK code Andy Lutomirski <luto@kernel.org> - 2016-07-11 23:00 +0200
Re: [PATCH v5 18/32] signal: Consolidate {TS,TLF}_RESTORE_SIGMASK code Brian Gerst <brgerst@gmail.com> - 2016-07-12 14:00 +0200
Re: [PATCH v5 18/32] signal: Consolidate {TS,TLF}_RESTORE_SIGMASK code Andy Lutomirski <luto@amacapital.net> - 2016-07-13 01:10 +0200
[PATCH v5 08/32] dma-api: Teach the "DMA-from-stack" check about vmapped stacks Andy Lutomirski <luto@kernel.org> - 2016-07-11 23:00 +0200
[PATCH v5 32/32] fork: Cache two thread stacks per cpu if CONFIG_VMAP_STACK is set Andy Lutomirski <luto@kernel.org> - 2016-07-11 23:00 +0200
[PATCH v5 27/32] x86: Move thread_info into task_struct Andy Lutomirski <luto@kernel.org> - 2016-07-11 23:00 +0200
[PATCH v5 31/32] sched: Free the stack early if CONFIG_THREAD_INFO_IN_TASK Andy Lutomirski <luto@kernel.org> - 2016-07-11 23:00 +0200
[PATCH v5 23/32] printk: When dumping regs, show the stack, not thread_info Andy Lutomirski <luto@kernel.org> - 2016-07-11 23:00 +0200
[PATCH v5 19/32] x86/smp: Remove stack_smp_processor_id() Andy Lutomirski <luto@kernel.org> - 2016-07-11 23:00 +0200
[PATCH v5 20/32] x86/smp: Remove unnecessary initialization of thread_info::cpu Andy Lutomirski <luto@kernel.org> - 2016-07-11 23:00 +0200
[PATCH v5 16/32] x86: Move uaccess_err and sig_on_uaccess_err to thread_struct Andy Lutomirski <luto@kernel.org> - 2016-07-11 23:00 +0200
[PATCH v5 04/32] x86/mm: Remove kernel_unmap_pages_in_pgd() and efi_cleanup_page_tables() Andy Lutomirski <luto@kernel.org> - 2016-07-11 23:10 +0200
[PATCH v5 01/32] bluetooth: Switch SMP to crypto_cipher_encrypt_one() Andy Lutomirski <luto@kernel.org> - 2016-07-11 23:10 +0200
Re: [PATCH v5 01/32] bluetooth: Switch SMP to crypto_cipher_encrypt_one() Andy Lutomirski <luto@amacapital.net> - 2016-07-14 21:20 +0200
Re: [PATCH v5 01/32] bluetooth: Switch SMP to crypto_cipher_encrypt_one() Marcel Holtmann <marcel@holtmann.org> - 2016-07-14 22:40 +0200
Re: [PATCH v5 01/32] bluetooth: Switch SMP to crypto_cipher_encrypt_one() David Miller <davem@davemloft.net> - 2016-07-14 22:50 +0200
[PATCH v5 05/32] mm: Track NR_KERNEL_STACK in KiB instead of number of stacks Andy Lutomirski <luto@kernel.org> - 2016-07-11 23:10 +0200
[PATCH v5 12/32] x86/dumpstack/64: Handle faults when printing the "Stack:" part of an OOPS Andy Lutomirski <luto@kernel.org> - 2016-07-11 23:10 +0200
[PATCH v5 06/32] mm: Fix memcg stack accounting for sub-page stacks Andy Lutomirski <luto@kernel.org> - 2016-07-11 23:10 +0200
[PATCH v5 03/32] x86/cpa: In populate_pgd, don't set the pgd entry until it's populated Andy Lutomirski <luto@kernel.org> - 2016-07-11 23:10 +0200
Re: [kernel-hardening] [PATCH v5 03/32] x86/cpa: In populate_pgd, don't set the pgd entry until it's populated Valdis.Kletnieks@vt.edu - 2016-07-22 06:50 +0200
Re: [kernel-hardening] [PATCH v5 03/32] x86/cpa: In populate_pgd, don't set the pgd entry until it's populated Andy Lutomirski <luto@kernel.org> - 2016-07-22 07:40 +0200
Re: [kernel-hardening] [PATCH v5 03/32] x86/cpa: In populate_pgd, don't set the pgd entry until it's populated Ingo Molnar <mingo@kernel.org> - 2016-07-22 12:30 +0200
Re: [kernel-hardening] [PATCH v5 03/32] x86/cpa: In populate_pgd, don't set the pgd entry until it's populated Andy Lutomirski <luto@amacapital.net> - 2016-07-22 20:30 +0200
Re: [kernel-hardening] [PATCH v5 03/32] x86/cpa: In populate_pgd, don't set the pgd entry until it's populated Andy Lutomirski <luto@amacapital.net> - 2016-07-22 20:40 +0200
Re: [kernel-hardening] [PATCH v5 03/32] x86/cpa: In populate_pgd, don't set the pgd entry until it's populated Ingo Molnar <mingo@kernel.org> - 2016-07-22 22:20 +0200
Re: [kernel-hardening] [PATCH v5 03/32] x86/cpa: In populate_pgd, don't set the pgd entry until it's populated Nicolai Stange <nicstange@gmail.com> - 2016-07-23 17:00 +0200
[PATCH v5 10/32] x86/dumpstack: Honor supplied @regs arg Andy Lutomirski <luto@kernel.org> - 2016-07-11 23:10 +0200
[PATCH v5 02/32] x86/mm/hotplug: Don't remove PGD entries in remove_pagetable() Andy Lutomirski <luto@kernel.org> - 2016-07-11 23:10 +0200
[PATCH v5 15/32] x86/mm: Improve stack-overflow #PF handling Andy Lutomirski <luto@kernel.org> - 2016-07-11 23:10 +0200
[PATCH v5 11/32] x86/dumpstack: Try harder to get a call trace on stack overflow Andy Lutomirski <luto@kernel.org> - 2016-07-11 23:10 +0200
Re: [PATCH v5 00/32] virtually mapped stacks and thread_info cleanup Herbert Xu <herbert@gondor.apana.org.au> - 2016-07-12 11:00 +0200
Re: [PATCH v5 00/32] virtually mapped stacks and thread_info cleanup Christian Borntraeger <borntraeger@de.ibm.com> - 2016-07-13 11:00 +0200
Re: [PATCH v5 00/32] virtually mapped stacks and thread_info cleanup Andy Lutomirski <luto@amacapital.net> - 2016-07-13 20:40 +0200
Re: [PATCH v5 00/32] virtually mapped stacks and thread_info cleanup Christian Borntraeger <borntraeger@de.ibm.com> - 2016-07-13 21:00 +0200
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